第二題

#include<iostream>
using std::cin;
using std::cout;
using std::endl;
class Complex
{
	private:
		double real;
		double imag;
	public:
		void display();
		Complex(){real=0;imag=0;}
        Complex(double r,double i){real=r;imag=i;}
        Complex operator+(Complex &c2);
        Complex operator-(Complex &c2);
        Complex operator*(Complex &c2);
        Complex operator/(Complex &c2);
};
Complex Complex::operator+(Complex &c2)
{      
    Complex c;
    c.real=real+c2.real;
	c.imag=imag+c2.imag;
    return c;
}
Complex Complex::operator-(Complex &c2)
{
    Complex c;
	c.real=real-c2.real;
	c.imag=imag-c2.imag;
	return c;
}
Complex Complex::operator*(Complex &c2)
{   
    Complex c;
    c.real=real*c2.real-imag*c2.imag;
	c.imag=imag*c2.real+real*c2.imag;
	return c;}

Complex Complex::operator/(Complex &c2)
{
   Complex c;
   c.real=(real*c2.real+imag*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag);
   c.imag=(imag*c2.real-real*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag);
   return c;
}

void Complex::display()
{
   cout<<"("<<real<<","<<imag<<"i)"<<endl;
}
int main()
{
	Complex c1(1,5),c2(2,-6),c3;
	cout<<"c1=";
	c1.display();
	cout<<"c2=";
	c2.display();
	c3=c1+c2;
	cout<<"c1+c2=";
	c3.display();
	c3=c1-c2;
	cout<<"c1-c2=";
	c3.display();
	c3=c1*c2;
	cout<<"c1*c2=";
	c3.display();
	c3=c1/c2;
	cout<<"c1/c2=";
	c3.display();
	return 0;
}